The field of this invention is that of combustion engines with fuel injection systems and relates more particularly to heaters for the fuel provided by such fuel injection systems.
Combustion engines with fuel injection are divided into engines with mechanical or electronic gasoline injection and diesel engines with injection of diesel fuel.
Compared with gasoline engines with a carburetor, an engine with fuel injection has the advantage that the fuel distribution is more efficient and that the engine reacts much more quickly and more accurately to changes in the position of the throttle, this being due to the short time elapsing between the movement of the throttle and the injection of the fuel. The power and acceleration are therefore clearly better in a fuel injection engine than in a carburetor engine. Electronic injection has the not inconsiderable advantage over mechanical injection that one can use temperature and pressure sensors to supply the cylinders with the correct amount of fuel in all circumstances. The quantity of fuel to be injected can be regulated by controlling the pressure (between, for example, 3 and 6 bars) or by regulation of the time. The outstanding advantages of fuel injection are offset by the disadvantage of a relatively poorer mixing of fuel and air; the air velocity is fairly low and there is little time available to mix fuel and air. Besides, the spray valve has a sparing spray action. These advantages are particularly felt when the engine is cold. The sparingly sprayed fuel, when poorly mixed with air, precipitates on the cold inlet passage and the cold cylinder wall.